Communications in spatial streams

ABSTRACT

In some examples, a first wireless device includes a network interface capable of communicating using 16 spatial streams; and at least one processor configured to allocate at least one spatial stream of the 16 spatial streams to a plurality of wireless devices, such that no wireless device of the plurality of wireless devices is allocated more than 4 spatial streams, and send a control information element indicating the allocation of the at least one spatial stream to the plurality of wireless devices.

BACKGROUND

A goal of successive generations of radio frequency communicationssystems is to apply techniques that can increase the amount ofinformation transmitted using communication resources as compared toprior techniques. In some examples, multiple-input and multiple-output(MIMO) communications can be employed. A MIMO communication refers to awireless communication in which multiple signals can be transmitted overone or more transmission resources by exploiting multipath propagation.The multipath propagation uses multiple spatial streams that carryrespective signals over the transmission resource.

In some cases, the number of spatial streams that can be used in awireless network can be restricted, such as by a governing wirelesscommunication standard. Restricting the number of spatial streams canresult in the wireless network not being able to support communicationdemands of wireless devices. Accordingly, there is a desire to increasethe number of available spatial streams while maintaining an acceptablelevel of signaling overhead.

SUMMARY

According to aspects of the present disclosure, a wireless network thatsupports multi-user multiple-input and multiple-output (MU-MIMO)communications can support up to 16 spatial streams for communicatingwith multiple wireless devices. At least one spatial stream from the 16spatial streams are allocated to a plurality of wireless devices, suchthat no wireless device of the plurality of wireless devices isallocated more than 4 spatial streams. A control information elementindicating the allocation of the at least one spatial stream is sent tothe plurality of wireless devices.

According to an aspect of the present disclosure, there is provided afirst wireless device comprising a network interface capable ofcommunicating using 16 spatial streams, and at least one processorconfigured to allocate at least one spatial stream of the 16 spatialstreams to a plurality of wireless devices, such that no wireless deviceof the plurality of wireless devices is allocated more than 4 spatialstreams, and send a control information element indicating theallocation of the at least one spatial stream to the plurality ofwireless devices.

According to another aspect of the present disclosure, there is provideda method performed by a first wireless device, the method comprisingallocating at least one spatial stream of 16 available spatial streamsto a plurality of wireless devices in a wireless network, such that nowireless device of the plurality of wireless devices is allocated morethan 4 spatial streams, and sending a control information elementindicating the allocation of spatial streams of the at least one spatialstream to the plurality of wireless devices.

According to a further aspect of the present disclosure, there isprovided a first wireless device comprising a network interface capableof communicating over a plurality of spatial streams, and anon-transitory storage medium to store a spatial configuration datastructure comprising a plurality of entries representing differentallocations of spatial streams to a plurality of wireless devices,wherein none of the different allocations of spatial streams allocatesmore than 4 spatial streams to a wireless device. At least one processoris configured to receive, from a second wireless device, a controlinformation element that maps to an entry of the plurality of entries,the entry mapped by the control information element comprising anallocation of spatial streams to at least some of the plurality ofwireless devices.

According to yet another aspect of the present disclosure, there isprovided a method performed by a first wireless device, the methodcomprising storing, in a storage medium, a spatial configuration datastructure comprising a plurality of entries representing differentallocations of spatial streams to a plurality of wireless devices,wherein none of the different allocations of spatial streams allocatesmore than 4 spatial streams to a wireless device, and receiving, from asecond wireless device, a control information element that maps to anentry of the plurality of entries, the entry mapped by the controlinformation element comprising an allocation of spatial streams to atleast some of the plurality of wireless devices.

Optionally, in any of the preceding aspects, in another implementation,the control information element comprises a value of a six-bit indexthat maps to a respective spatial configuration.

Optionally, in any of the preceding aspects, in another implementation,a non-transitory storage medium is to store a spatial configurationtable, wherein the spatial configurations are represented by differententries of the spatial configuration table.

Optionally, in any of the preceding aspects, in another implementation,the control information element further indicates how many wirelessdevices are allocated spatial streams.

Optionally, in any of the preceding aspects, in another implementation,the control information element is part of a preamble of a physical dataunit.

Optionally, in any of the preceding aspects, in another implementation,the control information element is part of a signal (SIG) field in aphysical header of a wireless local area network (WLAN) frame.

Optionally, in any of the preceding aspects, in another implementation,the control information element includes a user specific field of theSIG field, the user specific field further comprising a value indicatingthe allocation, and an identifier of a wireless device of the pluralityof wireless devices.

Optionally, in any of the preceding aspects, in another implementation,the control information element includes a common field of the SIGfield, the common field comprising a value indicating how many wirelessdevices are allocated spatial streams.

Optionally, in any of the preceding aspects, in another implementation,the first wireless device is able to communicate over the spatialstreams with up to a maximum of 16 wireless devices.

Optionally, in any of the preceding aspects, in another implementation,the first wireless device is an access point (AP).

Optionally, in any of the preceding aspects, in another implementation,the network interface is to perform multi-user multiple-input andmultiple-output (MU-MIMO) communications using up to the 16 spatialstreams.

Optionally, in any of the preceding aspects, in another implementation,a value is sent indicating how many wireless devices are allocatedspatial streams.

Optionally, in any of the preceding aspects, in another implementation,the control information element comprises a six-bit index that maps tothe entry of the spatial configuration data structure.

Optionally, in any of the preceding aspects, in another implementation,the control information element indicates how many wireless devices areallocated spatial streams, and the indication of how many wirelessdevices are allocated spatial streams maps to the entry of the spatialconfiguration data structure.

Optionally, in any of the preceding aspects, in another implementation,the control information element comprises a six-bit index that incombination with the indication of how many wireless devices areallocated spatial streams maps to the entry of the spatial configurationdata structure.

BRIEF DESCRIPTION OF THE DRAWINGS

Some implementations of the present disclosure are described withrespect to the following figures.

FIG. 1 is a block diagram of an example wireless arrangement thatincludes wireless devices capable of communications in spatial streams,according to some implementations of the present disclosure.

FIG. 2 is a block diagram of a control information element, according tosome examples.

FIGS. 3A-3E illustrate an example spatial configuration table, accordingto some implementations.

FIG. 4 is a block diagram of a wireless device according to someimplementations of the present disclosure.

FIG. 5 is a message flow diagram of a process according to someimplementations of the present disclosure.

Throughout the drawings, identical reference numbers designate similar,but not necessarily identical, elements. The figures are not necessarilyto scale, and the size of some parts may be exaggerated to more clearlyillustrate the example shown. Moreover, the drawings provide examplesand/or implementations consistent with the description; however, thedescription is not limited to the examples and/or implementationsprovided in the drawings.

DETAILED DESCRIPTION

In the present disclosure, use of the term “a,” “an”, or “the” isintended to include the plural forms as well, unless the context clearlyindicates otherwise. Also, the term “includes,” “including,”“comprises,” “comprising,” “have,” or “having” when used in thisdisclosure specifies the presence of the stated elements, but do notpreclude the presence or addition of other elements.

Multi-user multiple-input and multiple-output (MU-MIMO) refers to awireless communication technology that supports wireless communicationamong multiple wireless devices using multiple spatial streams. Thespatial streams are spatially distributed from one another. A sourcewireless device can transmit signals in the spatial streams to multiplerecipient wireless devices. The different spatial streams can carryinformation that is modulated or coded differently. For example, theinformation carried in a first spatial stream is modulated or codeddifferently than information in a second spatial stream.

The throughput available for wireless communications using the spatialstreams depends on the number of spatial streams that can be used forwireless communications. The Institute of Electrical and ElectronicsEngineers (IEEE) 802.11ax standard supports an MU-MIMO spatialconfiguration that allows for up to eight spatial streams to be used.Restricting the number of spatial streams to eight for MU-MIMOcommunications may result in a wireless network not being able to meetcommunication demands of wireless devices, as the number of wirelessdevices that are able to communicate in the wireless network continuesto grow.

In accordance with some implementations of the present disclosure, anMU-MIMO spatial configuration is provided that supports up to 16 spatialstreams for wireless communications. FIG. 1 is a block diagram of anexample wireless arrangement in which an access point (AP) 104 is ableto communicate with various electronic devices 106-1 to 106-N, N≥2, in awireless network 102.

The AP 104 and the electronic devices 106-1 to 106-N are examples ofwireless devices that are able to perform wireless communications.

In some examples, the AP 104 and electronic devices 106-1 to 106-N areable to communicate according to the Institute of Electrical andElectronic Engineers (IEEE) 802.11 group of standards. In such examples,the wireless network 102 is referred to as a wireless local area network(WLAN).

In other examples, the AP 104 and electronic devices 106-1 to 106-N cancommunicate according to other standards, such as wireless standardsincluding a Long-Term Evolution (LTE) standard as promulgated by theThird Generation Partnership Project (3GPP). In further examples, awireless standard can include a Fifth Generation (5G) 3GPP wirelessstandard. In a wireless network, an AP is referred to as a base station,such as an Evolved NodeB (eNB) for LTE.

Although just one AP 104 is shown in FIG. 1, it is noted that thewireless network 102 can include multiple APs that define respectivecoverage areas for communicating with electronic devices.

Examples of the electronic devices 106-1 and 106-2 include any or somecombination of the following: a desktop computer, a notebook computer, atablet computer, a smartphone, an Internet-of-Things (IoT) device (e.g.,a sensor, a camera, a thermostat, a household appliance, etc.), awearable device (e.g., a smartwatch, smart eyeglasses, a head-mounteddevice, etc.), a vehicle, server computers, storage devices,communication nodes, and so forth.

The AP 104 includes multiple transceivers 108 that are able tocommunicate with the electronic devices 106-1 to 106-N overcorresponding spatial streams 110-1, 110-2, . . . , 110-M. Generally, Mis greater than or equal to 2. In the example of FIG. 1, the AP 104communicates over multiple spatial streams 110-1 and 110-2 withrespective transceivers 109-1 the electronic device 106-1. The AP 104communicates over a spatial stream 110-M with a transceiver 109-N of theelectronic device 106-N. A “transceiver” includes a transmitter totransmit wireless signals, and a receiver to receive wireless signals.The transceiver can include an antenna and associated amplification andmodulation/demodulation circuitry. Each electronic device 106-i (i=1 toN) includes one or more transceivers 109-i.

In some examples, communications in the wireless network 102 between theAP 104 and the electronic devices 106-1 to 106-N can employ orthogonalfrequency-division multiple access (OFDMA) channels. According to somewireless standards, such as the IEEE 802.11ax standard, an OFDMA channelis subdivided into multiple resource units (RUs). The different RUs ofan OFDMA channel includes subcarriers of different frequencies. Each RUis a sub-channel of the OFDMA channel. Although reference is made toIEEE 802.11ax, it is noted that techniques or mechanisms according tosome implementations of the present disclosure can be used inconjunction with other standards, including future generations of theIEEE 802.11 standards or different standards.

In examples in which OFDMA RUs are used, the AP 104 can schedule MU-MIMOcommunications on one or more RUs. In other examples, MU-MIMO can bescheduled on other types of wireless transmission resources.

In accordance with some implementations of the present disclosure, theAP 104 is able to use an MU-MIMO spatial configuration that supportswireless communications with electronic devices over up to a maximum of16 spatial streams. A cap of a maximum of four spatial streams forwireless communication is set for each electronic device 106-i (i=1 toN). Stated differently, the number of spatial streams used by the AP 104for communicating with an individual electronic device 106-i does notexceed four spatial streams. Restricting the number of spatial streamsthat can be used with an individual electronic device to four spatialstreams allows for improved MU-MIMO communication performance ascompared to examples where more than four spatial streams can bescheduled for an individual electronic device.

Using 16 spatial streams as compared to eight spatial streams in awireless network can improve communication throughput of wirelessdevices over the spatial streams, because a larger number of spatialstreams can be divided among the wireless devices for use in datacommunications. With the increased number of spatial streams from eightto 16, the number of permutations of unique allocations of spatialstreams to wireless devices increases significantly. The spatial streamallocation permutations include allocations of different numbers ofspatial streams to respective wireless devices, which can vary dependingupon the number of wireless devices to which the spatial streams are tobe allocated.

With the large number of spatial stream allocation permutations,overhead associated with managing the allocation of spatial streams towireless devices can increase. For example, signaling overhead can beincreased due to use of an information element with a large number ofbits to represent which permutation to use. Additionally, storageoverhead can be increased if a data structure (referred to as a “spatialconfiguration table” in some examples and discussed further below)stored in a memory or other storage medium includes entriescorresponding to all of the possible spatial stream allocationpermutations.

By restricting the number of spatial streams that can be allocated toeach wireless device to four, the number of spatial stream allocationpermutations can be reduced. Reducing the number of spatial streamallocation permutations allows for use of an information element with asmaller number of bits to represent the different spatial streamallocations (as compared to the case where all of the possible spatialstream allocation permutations have to be signaled). Also, reducing thenumber of spatial stream allocation permutations means that the datastructure storing entries representing the different spatial streamallocations is smaller than the case where the data structure includesentries corresponding to all of the possible spatial stream allocationpermutations.

The AP 104 includes an MU-MIMO control engine 112 that is able tocontrol the scheduling of spatial streams for use with a collection ofelectronic devices. Each electronic device 106-1 to 106-N includes arespective MU-MIMO communication engine 114-1 to 114-N that is able tointeract with the MU-MIMO control engine 112 for performing MU-MIMOcommunications with the AP 104 over spatial streams allocated to therespective electronic device 106-i.

As used here, an “engine” can refer to a hardware processing circuit,which can include any or some combination of a microprocessor, a core ofa multi-core microprocessor, a microcontroller, a programmableintegrated circuit, a programmable gate array, a digital signalprocessor, or another hardware processing circuit. Alternatively, an“engine” can refer to a combination of a hardware processing circuit andmachine-readable instructions (software and/or firmware) executable onthe hardware processing circuit.

The MU-MIMO control engine 112 is able to send a control informationelement to each respective electronic device 106-i for controlling anallocation of one or more spatial streams to the electronic device106-i. An “information element” can refer to a message, a portion of amessage, or any other collection of information. The control informationelement can also include multiple portions (e.g., fields) of a message,or multiple messages. The control information element can be broadcastor multicast by the AP 104 to multiple electronic devices.Alternatively, the control information element can be unicast by the AP104 to an individual electronic device.

The MU-MIMO communication engine 114-i in the respective electronicdevice 106-i can receive the control information element, and determinean allocation of spatial streams for the electronic device 106-I basedon the control information element. Note that the allocated spatialstreams can include just one spatial stream or multiple spatial streams,up to a maximum of four spatial streams.

In some examples, the control information element includes a spatialconfiguration table index that can be set to one of multiple differentvalues to correspond to different entries of a spatial configurationtable. As shown in FIG. 1, the electronic devices 106-1 to 106-N storerespective spatial configuration tables 116-1 to 116-N. Each spatialconfiguration table 116-i is stored in a respective storage medium 117-iof the corresponding electronic device 106-i.

The AP 104 also stores its copy of the spatial configuration table 120in a storage medium 122 of the AP 104. A storage medium in the AP 104 oran electronic device 106-i can include one or more storage devices,including any or some combination of a disk-based storage device, asolid-state drive, a memory device, and so forth.

In some implementations of the present disclosure, the spatialconfiguration table index is six bits in length. The spatialconfiguration table index can be set to six bits in length because thenumber of spatial stream allocation permutations has been reduced basedon capping the number of spatial streams to each wireless device to amaximum of four. Without capping the number of spatial streams to eachwireless device to a maximum of four, a six-bit spatial configurationtable index would not be sufficient to represent all of the possiblespatial configuration allocation permutations.

The control information element sent by the AP 104 can also include aparameter set to a value that identifies a number of electronic devicesthat are participating in MU-MIMO communications. As used here, a“number” of electronic devices refers to a quantity of electronicdevices, i.e., how many electronic devices have been allocated spatialstreams. The combination of the number of electronic devices and thespatial configuration table index included in the control informationelement maps to a respective entry of the spatial configuration table.The MU-MIMO communication engine 114-i of each electronic device 106-iparticipating in the MU-MIMO communications accesses the respectiveentry of the spatial configuration table to determine the respectiveallocation of spatial streams to that electronic device 106-i.

FIG. 2 illustrates an example control information element 200. In someexamples, the control information element 200 can be in the form of asignal (SIG) field in a physical (PHY) header of a WLAN frame. In otherexamples, the control information element 200 can be part of a differentfield or different message (or part of multiple fields or messages). Forexample, the control information element 200 can be part of the preambleof a physical data unit.

The control information element 200 includes a common field 202 and oneor more user-specific fields 204-1 to 204-P (P≥2 in examples in whichthe control information element 200 includes more than one user-specificfield). The common field 202 can include a parameter 206 set to a valuethat specifies a number of electronic devices being scheduled forMU-MIMO communications. For example, up to 16 electronic devices can bescheduled for MU-MIMO communications by the AP 104.

Each user-specific field 204-j (j=1 to P) includes information specificto a respective individual electronic device. A user-specific field204-j includes a device identifier 208-j (such as a station or STAidentifier) to identify the respective electronic device. In addition,the user-specific field 204-j includes a spatial configuration tableindex 210-j (six bits in length in some implementations) that incombination with the parameter 206 maps to a respective entry of thespatial configuration table. The user-specific field 204-j can includefurther information in further examples.

In the example of FIG. 2, the user-specific field 204-j containsinformation specific to the electronic device identified by the deviceID 208-j in the user-specific field 204-j.

An example of a spatial configuration table 300 according to someimplementations of the present disclosure is shown in FIGS. 3A-3E. Aninstance of the spatial configuration table 300 can be stored in the AP104 and in each of the electronic devices 106-1 to 106-N.

In the spatial configuration table 300, an N_STA column 302 includes avalue of the parameter 206 (FIG. 2) included in the common field 202 forspecifying the number of electronic devices being scheduled for MU-MIMOcommunications. Different values of N_STA map to different spatialconfiguration table parts (304-1 to 304-15) of the spatial configurationtable 300. The spatial configuration table part 304-1 of the spatialconfiguration table 300 contains entries for a scenario in which twoelectronic devices are scheduled for MU-MIMO communications, the spatialconfiguration table part 304-2 of the spatial configuration table 300contains entries for a scenario in which three electronic devices arescheduled for MU-MIMO communications, the spatial configuration tablepart 304-3 of the spatial configuration table 300 contains entries for ascenario in which four electronic devices are scheduled for MU-MIMOcommunications, and so forth, up to the spatial configuration table part304-15 of the spatial configuration table 300 that contains entries fora scenario in which 16 electronic devices are scheduled for MU-MIMOcommunications.

An index column 306 includes different values of the spatialconfiguration table index, implemented with six bits B5, B4, B3, B2, B1,B0.

An Nsts(1) column specifies the number of spatial streams allocated toelectronic device 1, an Nsts(2) column specifies the number of spatialstreams allocated to electronic device 2, an Nsts(3) specifies thenumber of spatial streams allocated to electronic device 3, and soforth, up to an Nsts(16) column, which specifies the number of spatialstreams allocated to electronic device 16. Note that a blank in a givenNsts(i) column indicates that the allocation of spatial streams in thecorresponding entry of the spatial configuration table 300 does notapply to the corresponding electronic device i (i=1 to 16).

A Total N_STS column of the spatial configuration table 300 indicates anumber of spatial streams allocated to MU-MIMO scheduled electronicdevices. A Number of Entries column specifies the number of entriespresent in the respective part of the spatial configuration table 300.For example, the Number of Entries value for the spatial configurationtable part 304-1 is 10, which indicates that the spatial configurationtable part 304-1 includes 10 entries corresponding to 10 possible values(000000 to 001001) of the spatial configuration table index included inthe index column 306.

In the spatial configuration table part 304-1 corresponding to N_STA=2,the range of index values of the spatial configuration table index is000000 to 001001.

The four possible values (000000, 000001, 000010, and 000011) in thespatial configuration table index range of 000000-000011 correspond torespective different numbers of spatial streams allocated to electronicdevice 1. For example, if the spatial configuration table index is setto 000000, and N_STA=2, then the number of spatial streams allocated toelectronic device 1 in the Nsts(1) column is 1 and the number of spatialstreams allocated to electronic device 2 in the Nsts(2) column is 1(note that in this entry of the spatial configuration table 300, theother electronic devices 3 to 16 are not allocated any spatial streams).If the spatial configuration table index is set to 000001 and theN_STA=2, then the number of spatial streams allocated to electronicdevice 1 in the Nsts(1) column is 2 and the number of spatial streamsallocated to electronic device 2 in the Nsts(2) column is 1 (note thatin this entry of the spatial configuration table 300, the otherelectronic devices 3 to 16 are not allocated any spatial streams). Ifthe spatial configuration table index is set to 000010 and N_STA=2, thenthe number of spatial streams allocated to electronic device 1 in theNsts(1) column is 2 and the number of spatial streams allocated toelectronic device 2 in the Nsts(2) column is 1 (note that in this entryof the spatial configuration table 300, the other electronic devices 3to 16 are not allocated any spatial streams). If the spatialconfiguration table index is set to 000011 and N_STA=2, then the numberof spatial streams allocated to electronic device 1 in the Nsts(1)column is 4 and the number of spatial streams allocated to electronicdevice 2 in the Nsts(2) column is 1 (note that in this entry of thespatial configuration table 300, the other electronic devices 3 to 16are not allocated any spatial streams).

If the spatial configuration table index is set to 000100 and N_STA=2,then the number of spatial streams allocated to electronic device 1 inthe Nsts(1) column is 2 and the number of spatial streams allocated toelectronic device 2 in the Nsts(2) column is 2 (note that in this entryof the spatial configuration table 300, the other electronic devices 3to 16 are not allocated any spatial streams).

The other entries of the spatial configuration table part 304-1 areconstrued similarly.

In another example for N_STA=4 (which maps to the spatial configurationtable part 304-3), if the spatial configuration table index is set to001111, then the number of spatial streams allocated to electronicdevice 1 in the Nsts(1) column is 4, the number of spatial streamsallocated to electronic device 2 in the Nsts(2) column is 4, the numberof spatial streams allocated to electronic device 3 in the Nsts(3)column is 2, and the number of spatial streams allocated to electronicdevice 4 in the Nsts(4) column is 1 (note that in this entry of thespatial configuration table 300, the other electronic devices 5 to 16are not allocated any spatial streams).

The remainder of the spatial configuration table 300 is construedsimilarly.

In the example of FIG. 3, certain combinations of N_STA values andspatial configuration table index values map to spatial configurationsin which more than eight and up to 16 spatial streams are allocated toelectronic devices.

FIG. 4 is a block diagram of a wireless device 400, which can be the AP104 of FIG. 1 or an electronic device 106-i of FIG. 1. The wirelessdevice 400 includes one or more hardware processors 402. A hardwareprocessor can include a microprocessor, a core of a multi-coremicroprocessor, a microcontroller, a programmable integrated circuit, aprogrammable gate array, a digital signal processor, or another hardwareprocessing circuit.

The wireless device 400 further includes a network interface 404 tocommunicate over a wireless network (e.g., 102 in FIG. 1). The networkinterface 404 includes transceivers and network protocol layers to allowfor communications over the wireless network.

The wireless device 400 also includes a non-transitory machine-readableor computer-readable storage medium 406 that stores machine-readableinstructions executable on the one or more hardware processors 402 toperform respective tasks.

The machine-readable instructions include MU-MIMO-related instructions408, which upon execution on the one or more hardware processors 402 canperform the tasks of the MU-MIMO control engine 112 of FIG. 1, or thetasks of the MU-MIMO communication engine 114-i of FIG. 1.

For example, the MU-MIMO-related instructions 408 can send a controlinformation element including a value (e.g., of a spatial configurationtable index) selected from multiple values that correspond to differentspatial configurations (having different allocations of spatial streams)of the 16 spatial streams to multiple wireless devices. Each wirelessdevice is allocated up to a maximum of four spatial streams. The spatialconfiguration table index can be a six-bit index.

FIG. 5 is a flow diagram of a process that can be performed by the AP104 and an electronic device 106, according to some examples. The APtransmits (at 502) a control information element that includes an N_STAparameter (specifying a number of electronic devices involved inscheduling for MU-MIMO communications by the AP 104) and a spatialconfiguration table index.

In response to receiving the control information element, the electronicdevice 106 accesses (at 504) an entry of the spatial configuration table(e.g., 300 in FIG. 3) stored in the electronic device 106. The accessedentry of the spatial configuration table is mapped to a combination ofthe N_STA parameter value and the spatial configuration table index. Theaccessed entry includes an allocation of spatial streams (one or more)for the electronic device 106.

The electronic device 106 uses the allocated spatial stream(s), asindicated by the accessed entry of the spatial configuration table, tocommunicate (at 506) with the AP 104. For example, the electronic device106 receives information in the allocated spatial stream(s) from the AP104.

A storage medium (e.g., 406 in FIG. 4) can include any or somecombination of the following: a semiconductor memory device such as adynamic or static random access memory (a DRAM or SRAM), an erasable andprogrammable read-only memory (EPROM), an electrically erasable andprogrammable read-only memory (EEPROM) and flash memory; a magnetic disksuch as a fixed, floppy and removable disk; another magnetic mediumincluding tape; an optical medium such as a compact disc (CD) or adigital video disc (DVD); or another type of storage device. Note thatthe instructions discussed above can be provided on onecomputer-readable or machine-readable storage medium, or alternatively,can be provided on multiple computer-readable or machine-readablestorage media distributed in a large system having possibly pluralnodes. Such computer-readable or machine-readable storage medium ormedia is (are) considered to be part of an article (or article ofmanufacture). An article or article of manufacture can refer to anymanufactured single component or multiple components. The storage mediumor media can be located either in the machine running themachine-readable instructions, or located at a remote site from whichmachine-readable instructions can be downloaded over a network forexecution.

In the foregoing description, numerous details are set forth to providean understanding of the subject disclosed herein. However,implementations may be practiced without some of these details. Otherimplementations may include modifications and variations from thedetails discussed above. It is intended that the appended claims coversuch modifications and variations.

What is claimed is:
 1. A first wireless device comprising: anon-transitory storage medium to store a spatial configuration tableincluding different entries representing different spatialconfigurations that correspond to different allocations of spatialstreams to a plurality of wireless devices; a network interface capableof communicating using 16 spatial streams; and at least one processorconfigured to: allocate at least one spatial stream of the 16 spatialstreams to the plurality of wireless devices, such that no wirelessdevice of the plurality of wireless devices is allocated more than 4spatial streams, and send a control information element indicating theallocation of the at least one spatial stream to the plurality ofwireless devices, wherein the control information element comprises avalue of a six-bit index that maps to a respective spatial configurationof the different spatial configurations of the spatial configurationtable.
 2. The first wireless device of claim 1, wherein the controlinformation element further indicates how many wireless devices areallocated spatial streams.
 3. The first wireless device of claim 1,wherein the control information element is part of a preamble of aphysical data unit.
 4. The first wireless device of claim 1, wherein thecontrol information element is part of a signal (SIG) field in aphysical header of a wireless local area network (WLAN) frame.
 5. Thefirst wireless device of claim 4, wherein the control informationelement includes a user specific field of the SIG field, the userspecific field further comprising the value of the six-bit index, and anidentifier of a wireless device of the plurality of wireless devices. 6.The first wireless device of claim 5, wherein the control informationelement includes a common field of the SIG field, the common fieldcomprising a value indicating how many wireless devices are allocatedspatial streams.
 7. The first wireless device of claim 1, wherein thefirst wireless device is able to communicate over the spatial streamswith up to a maximum of 16 wireless devices.
 8. The first wirelessdevice of claim 1, wherein the first wireless device is an access point(AP).
 9. The first wireless device of claim 1, wherein the networkinterface is to perform multi-user multiple-input and multiple-output(MU-MIMO) communications using up to the 16 spatial streams.
 10. Thefirst wireless device of claim 1, wherein the control informationelement further comprises a parameter that is set to a parameter valuespecifying how many wireless devices are allocated spatial streams,wherein a combination including the value of the six-bit index and theparameter value of the parameter maps to a respective entry of theentries in the spatial configuration table.
 11. A method performed by afirst wireless device, comprising: storing a spatial configuration tablein a storage medium of the first wireless device, wherein the spatialconfiguration table includes different entries representing differentspatial configurations that correspond to different allocations ofspatial streams to a plurality of wireless devices; allocating at leastone spatial stream of 16 available spatial streams to the plurality ofwireless devices in a wireless network, such that no wireless device ofthe plurality of wireless devices is allocated more than 4 spatialstreams; and sending a control information element indicating theallocation of the at least one spatial stream of the 16 availablespatial streams to the plurality of wireless devices, wherein thecontrol information element comprises a value of a six-bit index thatmaps to a respective spatial configuration of the different spatialconfigurations of the spatial configuration table.
 12. The method ofclaim 11, further comprising: sending a value indicating how manywireless devices are allocated spatial streams.
 13. The method of claim11, wherein the control information element is part of a preamble of aphysical data unit.
 14. The method of claim 11, wherein the controlinformation element is part of a signal (SIG) field in a physical headerof a wireless local area network (WLAN) frame.
 15. The method of claim14, wherein the control information element includes a user specificfield of the SIG field, the user specific field comprising the value ofthe six-bit index and an identifier of a wireless device of theplurality of wireless devices.
 16. The method of claim 15, wherein thecontrol information element includes a common field of the SIG field,the common field comprising a parameter set to a value specifying howmany wireless devices are allocated spatial streams.
 17. The method ofclaim 11, wherein the first wireless device is able to communicate overthe spatial streams with up to a maximum of sixteen wireless devices.18. The method of claim 11, wherein the control information elementfurther comprises a parameter that is set to a parameter valuespecifying how many wireless devices are allocated spatial streams,wherein a combination including the value of the six-bit index and theparameter value of the parameter maps to a respective entry of theentries in the spatial configuration table.
 19. A first wireless devicecomprising: a network interface capable of communicating over aplurality of spatial streams; a non-transitory storage medium to store aspatial configuration data structure comprising a plurality of entriesrepresenting different allocations of spatial streams to a plurality ofwireless devices, wherein none of the different allocations of spatialstreams allocates more than 4 spatial streams to a wireless device; andat least one processor configured to receive, from a second wirelessdevice, a control information element that maps to an entry of theplurality of entries, wherein the control information element comprisesa six-bit index that maps to the entry of the spatial configuration datastructure, the entry mapped by the control information elementcomprising an allocation of spatial streams to at least some of theplurality of wireless devices.
 20. The first wireless device of claim19, wherein the control information element indicates how many wirelessdevices are allocated spatial streams, and the indication of how manywireless devices are allocated spatial streams maps to the entry of thespatial configuration data structure.
 21. The first wireless device ofclaim 20, wherein the six-bit index in combination with the indicationof how many wireless devices are allocated spatial streams maps to theentry of the spatial configuration data structure.
 22. The firstwireless device of claim 19, wherein the control information element ispart of a signal (SIG) field in a physical header of a wireless localarea network (WLAN) frame.
 23. The first wireless device of claim 22,wherein the control information element includes a user specific fieldof the SIG field, the user specific field comprising the six-bit indexand an identifier of a wireless device of the plurality of wirelessdevices.
 24. The first wireless device of claim 23, wherein the controlinformation element includes a common field of the SIG field, the commonfield comprising a parameter set to a value specifying how many wirelessdevices are allocated spatial streams.
 25. The first wireless device ofclaim 19, wherein the control information element further comprises aparameter that is set to a parameter value specifying how many wirelessdevices are allocated spatial streams, wherein a combination including avalue of the six-bit index and the parameter value of the parameter mapsto a respective entry of the entries in the spatial configuration datastructure.
 26. A method performed by a first wireless device,comprising: storing, in a storage medium, a spatial configuration datastructure comprising a plurality of entries representing differentallocations of spatial streams to a plurality of wireless devices,wherein none of the different allocations of spatial streams allocatesmore than 4 spatial streams to a wireless device; and receiving, from asecond wireless device, a control information element that maps to anentry of the plurality of entries, wherein the control informationelement comprises a six-bit index that maps to the entry of the spatialconfiguration data structure, the entry mapped by the controlinformation element comprising an allocation of spatial streams to atleast some of the plurality of wireless devices.
 27. The method of claim26, wherein the control information element indicates how many wirelessdevices are allocated spatial streams, and the indication of how manywireless devices are allocated spatial streams maps to the entry of thespatial configuration data structure.